Reversing gear



R. MEYER nEvEnsING GEAR Filed Jan. 11, 1928 Aug. 27, 1929.

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Patented Aug. 27, 1929. i 1' i UNITED STATES PATENT OFI-"ics,-

RUDOLF MEYER, OF BAMBERG, GERMANY.

REVERSING GEAR.

Application led January 11, 1928, Serial No. 245,897, and in Germany July 8, 1927.

This invention relates to a reversing gear lever a is mounted so that it can be turned with automatic reversing, which is free from transversely to the control shaft f. This lecertain inconveniences connected with the ver a is connected by a rod s with a lever arm reversing gears of known types. rIhe gears t the end Z) of whichis bent at right angles working with clutches or friction wheels are and has an inclined end surface adapted to co defective in so far as theV pressure to be eX- act upon the friction wheel c. A similar leerted by the clutch elements has to. be prover arm might be arranged behind the fricv duced by springs, weights, levers or the like, tion wheel c.

Wherefrom results an unfavorable efficiency, In the drawing, the reversing gear is 1o frequent readjusting being necessary. The shown in the normal, inoperative position. es travel in both directions of movement is To set the reversing gear in operation, the never accurately the same. Reversing gears lever a is turned so that the inclined end working with eccentricsV or links possess the .face b of the lever arm t is removed from the inconvenience, that the speed is not uniform. friction wheel o. The friction wheel c is Owing to the utilization of cams and the then pressed by the action of spring (Z To like, the last mentioned reversing gears are against the bevel pinion c of the driving comparatively expensive. The reversing shaft m so that the control shaft f is rotated gears of all these types can further not be by the friction wheel c', the driven shaft 'a stopped accurately at predetermined posibeing rotated by the worm g1 and worm tion of the machine tool. wheel g. Owing to the resistance of the These inconveniences are obviatedA by the worm wheel g the thrust of the worm acts invention by utilizing for the pressing presin the direction of the arrow t and pulls-the sure of the coupling elements the thrust of control shaft f strongly in the direction z'. a worm, a screw or a worm wheel,the reverswhereby the friction wheel ol is strongly ing being effected by a nuttravelling on a. 'pulledk against the bevel pinion e in accordso spindle and stopped at certain points s0 ance with the energy taken up by the worm that the spindle is then shifted and reverses wheel g. The nut e' travels, owing to the rothe driven shaft. tation of the spindle j, in the direction it An embodiment of the invention is illusuntil it strikes against the end wall le of the 3o trated, by way of example, in the only figcasing so that it is stopped, the shaft 7' beure of the accompanying drawing in longinning then to shift in the direction of the gitudinal section. arrow t, whereby the friction wheel o is The driven shaft n of the machine tool is disengaged from the pinion c, the friction driven from the driving shaft m through the wheel 0 being brought into gear with said intermediary of a control shaft f. As coupinion e. The short idle run in the travel- 90 pling elements conical friction wheels are ling movement of nut z' between this disenused for example, but any other coupling gaging and re-engaging is overcome by the or clutch-elements might be used. On the action of the centrifugal force of the rotatdriving shaft m a bevel pinion eis keyed ing elements of the gear. rlhe spring l pre- 40 and on the control shaft f two friction bevel vents jerk-wise stopping of the gear. After 95 wheels c and c are shiftably mounted. Bethe reversing the nut i travels in the direchind each friction wheel c, c an, abutment tion h. until it strikes against the abutment p, p respectively is fixed on the control shaft lo of the casing, so that the reversing takes f, spiral springs 6E, d respectively being en place again. closed between the corresponding,abutment For disengaging, the lever a has to be 100 and friction wheel. turned. The control mechanism shown in A worm g is further mounted on the conthe drawing, according to which at the retrol shaft y, a worm wheel g on the driven versing the disengaging of the one friction shaft n meshing with said worm. The porwheel is effected or prepared, the engaging tion of the control shaft fwhich is located of the other friction wheel being however 105 in a casing formed between two end walls prevented, makes it possible to stop the c, 7c is constructed as a screw spindle f on driven machine accurately at a predeterwhich a nut c' is screwed which is guided in vmined moment.

a longitudinal groove r of the casing and se- Instead of the friction wheels shown,

cured against rotation. On the casing a clutches might be used, and for the worm 11o and Worm Wheel helical wheels or a screw might be substituted. The reversing gear is adapted to be used also for accelerated backward movement and for adjustable speeds.

`I claim l. A reversing gear with automatic reversing, comprising in combination with the driving shaft and the driven shaft, a shiftable control-shaft between said driving shaft and said driven shaft, a bevel pinion on the end of the driving shaft, two bevel friction wheels shiftably keyed on said control shaft, a spring acting on the rear side of each friction wheel, an abutment for each spring on said control shaft, said springs pressing alternately one of said friction wheels against said driving pinion, a worm on said control-shaft, and a worm wheel on said driven shaft meshing with said worm and producing by its working resistance an axial thrust upon said control shaft alternately in the one or other direction so that the spring abutment of the friction Wheels acts alternately on the corresponding spring whereby the corresponding friction wheel is brought into engagement with said bevel pinion, and an automatic reversing mechanism for the shiftable control-shaft.

2. A reversing gear with automatic reversing, comprising in combination with the driving shaft and the driven shaft, a shiftable control-shaft between said driving shaft and said 'driven shaft, a bevel'pinion on the end of the driving shaft, two bevel friction wheels keyed on said control shaft, a spring acting on the rear side of each friction wheel, an abutment for each spring on said control shaft, said springs pressing alternately one of said friction wheels against said driving pinion, a worm on said controlshaft, a Worm wheel on said driven shaft meshing with said worm and producing by its working resistance an axial thrust upon said vcontrol shaft alternately in the one or other direction so that the spring abutment of the friction wheels acts alternately on the corresponding spring whereby the corresponding friction wheel is brought into engagement with said bevel pinion, a spindle on said control shaft, a nut on said spindle, a casing enclosing said spindle and said nut, a brakingvdevice for stopping said nut alternat-ingly 'at the one or other end of its travel so that said control `shaft is shifted and the other friction wheel is brought into gear with saidL driving gear whereby the direction of rotation of the` control shaft is reversed, and a control device for engaging or disengaging said reversing` gear. 3. In a reversing gear with automatic reversing as specifiedy in claim 2, in con'ibination with said friction wheels and the spindle portion of said control shaft and nut, a casing in which said nut is loca-ted, an abutment at each end of said casing for limiting the travel of said nut rto stop the saine at the end of each travel for shifting said vcontrol shaft and altering the engaging of said friction Wheels and the direction of rotation of said control shaft. l l l 4. In a reversing gear with automatic reversing as specified in claim 2, in combination with said driving pinion, control shaft, casing and friction bevel Wheels, lar hand lever pivotally moudntedon saidcasing, a rod parallel to said control shaft extending 'from said hand lever to behind one of said friction bevel wheels, and a lever arm at the free end ofv said rod bent at right angles and having an inclined end face designed to act onto the corresponding friction Wheel to prevent the same from y coming into 'gear with the friction pinion.

In testimony whereof Iafix my signature.

RUDOLF MEYER. 

